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Radon Levels, Testing and Mitigation in South Carolina

South Carolina has 46 counties, with 1 classified as EPA Zone 1 (highest risk). With an average radon level of 6.84 pCi/L, South Carolina state testing data reveals significantly elevated risks across multiple counties. Testing is highly recommended.

South Carolina is the 40th most expansive state in terms of size and the 24th most populous in the entire US.

South Carolina does have an active radon program, dedicated to educating citizens about the risks associated with the deadly gas. You can find more information on Radon, testing and mitigation at the official page.

6.84
Avg. pCi/L
46
Counties
1
Zone 1 Counties

South Carolina Radon Map

South Carolina radon levels by county
Zone 1 — High
Zone 2 — Moderate
Zone 3 — Low

South Carolina Metro Areas

Explore radon data organized by metro region, including average levels, hotspot cities, and local mitigation professionals.

Augusta Metro
5 cities
Charleston Metro
5 cities
Charlotte Metro
5 cities
Columbia Metro
5 cities
Florence Metro
5 cities
Greenville Metro
5 cities
Hilton Head Island Metro
5 cities
Myrtle Beach Metro
5 cities
Spartanburg Metro
5 cities

Most Active Radon Markets in South Carolina

Cities with the most user-submitted radon test data, ranked by number of submissions.

CityAvg User Radon LevelSubmissions
Fort Mill 6.00 pCi/L 1
Greenville 5.00 pCi/L 1

South Carolina Counties by EPA Radon Zone

All 46 South Carolina counties with their EPA radon zone classification and user-submitted average radon levels.

Zone 1 — High Risk
Predicted avg. indoor levels > 4.0 pCi/L
Zone 1 1 counties
Greenville County Zone 1
Avg: 5.8 pCi/L
Zone 2 — Moderate Risk
Predicted avg. indoor levels 2–4 pCi/L
Zone 2 8 counties
Abbeville County Zone 2
Avg:
Anderson County Zone 2
Avg: 8.5 pCi/L
Cherokee County Zone 2
Avg: 5.0 pCi/L
Laurens County Zone 2
Avg:
Oconee County Zone 2
Avg: 8.0 pCi/L
Pickens County Zone 2
Avg: 8.0 pCi/L
Spartanburg County Zone 2
Avg: 4.0 pCi/L
York County Zone 2
Avg: 8.0 pCi/L
Zone 3 — Low Risk
Predicted avg. indoor levels < 2 pCi/L
Zone 3 37 counties
Aiken County Zone 3
Avg:
Allendale County Zone 3
Avg:
Bamberg County Zone 3
Avg:
Barnwell County Zone 3
Avg:
Beaufort County Zone 3
Avg:
Berkeley County Zone 3
Avg:
Calhoun County Zone 3
Avg: 5.0 pCi/L
Charleston County Zone 3
Avg:
Chester County Zone 3
Avg:
Chesterfield County Zone 3
Avg:
Clarendon County Zone 3
Avg:
Colleton County Zone 3
Avg:
Darlington County Zone 3
Avg:
Dillon County Zone 3
Avg:
Dorchester County Zone 3
Avg:
Edgefield County Zone 3
Avg:
Fairfield County Zone 3
Avg: 15.0 pCi/L
Florence County Zone 3
Avg:
Georgetown County Zone 3
Avg: 3.0 pCi/L
Greenwood County Zone 3
Avg:
Hampton County Zone 3
Avg:
Horry County Zone 3
Avg:
Jasper County Zone 3
Avg:
Kershaw County Zone 3
Avg:
Lancaster County Zone 3
Avg: 4.0 pCi/L
Lee County Zone 3
Avg:
Lexington County Zone 3
Avg: 5.5 pCi/L
Marion County Zone 3
Avg:
Marlboro County Zone 3
Avg:
McCormick County Zone 3
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Newberry County Zone 3
Avg:
Orangeburg County Zone 3
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Richland County Zone 3
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Saluda County Zone 3
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Sumter County Zone 3
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Union County Zone 3
Avg:
Williamsburg County Zone 3
Avg:

South Carolina Cities & Towns

Browse radon data for individual cities across South Carolina. Each city page includes user-submitted radon levels, local contractors, and mitigation resources.

Abbeville Adams Run Aiken Alcolu Allendale Anderson Andrews Awendaw Aynor Bamberg Barnwell Batesburg Beaufort Beech Island Belton Bennettsville Bethune Bishopville Blacksburg Blackstock Blackville Blair Blenheim Bluffton Blythewood Boiling Springs Bonneau Bowman Bradley Branchville Brunson Buffalo Cades Calhoun Falls Camden Cameron Campobello Carlisle Cassatt Catawba Cayce Central Chapin Chappells Charleston Charleston Afb Cheraw Chesnee Chester Chesterfield Clarks Hill Clemson Cleveland Clinton Clio Clover Columbia Conway Coosawhatchie Cope Cordesville Cordova Cottageville Coward Cowpens Cross Cross Hill Dalzell Darlington Daufuskie Island Denmark Dillon Donalds Dorchester Due West Duncan Early Branch Easley Eastover Edgefield Edgemoor Edisto Island Effingham Ehrhardt Elgin Elloree Enoree Estill Eutawville Fair Play Fairfax Florence Fork Fort Lawn Fort Mill Fountain Inn Gable Gadsden Gaffney Galivants Ferry Garnett Gaston Georgetown Gilbert Gloverville Goose Creek Graniteville Gray Court Great Falls Greeleyville Green Pond Green Sea Greenville Greenwood Greer Gresham Hamer Hampton Hanahan Hardeeville Harleyville Hartsville Heath Springs Hemingway Hickory Grove Hilton Head Island Hodges Holly Hill Hollywood Honea Path Hopkins Huger Inman Irmo Islandton Isle Of Palms Iva Jackson Jamestown Jefferson Jenkinsville Joanna Johns Island Johnsonville Johnston Jonesville Kershaw Kinards Kingstree Ladson Ladys Island Lake City Lake View Lamar Lancaster Landrum Lane Latta Laurens Leesville Lexington Liberty Little Mountain Little River Little Rock Lodge Long Creek Longs Loris Lugoff Luray Lyman Lynchburg Manning Marietta Marion Martin Mauldin Mayesville Mc Bee Mc Clellanville Mc Coll Mc Connells Mc Cormick Modoc Moncks Corner Monetta Moore Mount Carmel Mount Croghan Mount Pleasant Mountain Rest Mountville Mullins Murrells Inlet Myrtle Beach Neeses Nesmith New Ellenton New Zion Newberry Nichols Ninety Six Norris North North Augusta North Charleston North Myrtle Beach Norway Okatie Olanta Olar Orangeburg Pacolet Pageland Pamplico Patrick Pauline Pawleys Island Pelion Pelzer Pendleton Pickens Piedmont Pineland Pineville Pinewood Pinopolis Plum Branch Pomaria Port Royal Prosperity Ravenel Reevesville Rembert Richburg Ridge Spring Ridgeland Ridgeville Ridgeway Rock Hill Roebuck Round O Rowesville Ruby Ruffin Saint George Saint Helena Island Saint Matthews Saint Stephen Salem Salley Salters Saluda Santee Scranton Seabrook Sellers Seneca Sharon Shaw A F B Sheldon Silverstreet Simpsonville Six Mile Smoaks Smyrna Society Hill Spartanburg Springfield Starr Sullivans Island Summerton Summerville Sumter Sunset Swansea Tamassee Taylors Tillman Timmonsville Townville Travelers Rest Trenton Troy Turbeville Ulmer Union Vance Varnville Wadmalaw Island Wagener Walhalla Wallace Walterboro Ward Ware Shoals Warrenville Waterloo Wedgefield Wellford West Columbia West Union Westminster Westville Whitmire Williamston Williston Windsor Winnsboro Woodruff Yemassee York

Frequently Asked Questions About Radon in South Carolina

What radon level is considered "high"?
The EPA action level is 4.0 pCi/L — many homeowners also choose to fix levels between 2.0 and 4.0 pCi/L. Any home with levels at or above 4.0 pCi/L should be mitigated.
How much does radon mitigation cost in South Carolina?
Radon mitigation typically costs between $800 and $2,500, depending on foundation type and radon severity. A standard sub-slab depressurization system usually falls in the $1,000–$1,500 range.
Does mitigation actually work?
Yes — properly installed systems typically reduce radon levels by up to 99%. A post-mitigation test confirms the system is working correctly, and many homeowners re-test periodically.
Should I test again after mitigation?
Yes. A post-mitigation test is the proof your system is working. The EPA recommends testing within 30 days of installation and retesting every two years.
What EPA Radon Zone is my South Carolina county in?
South Carolina counties are classified into three EPA Radon Zones. Zone 1 (highest risk, >4 pCi/L) indicates the most concern. Zone 2 (moderate, 2–4 pCi/L) and Zone 3 (lowest, <2 pCi/L) round out the classification. Use the county directory above to find your specific county's zone and data.

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